Anycast vs Unicast What a Global Business Needs to Know Anycast vs Unicast: What a Global Business Needs to Know 1 In today’s online marketplace, global businesses must make sure their customers around the world can access their content, applications, and data whenever and wherever they need them. One of the best ways to provide 100% uptime and high performance is by integrating anycast routing into your infrastructure. What is Anycast? The easiest way to understand how anycast routing works is to compare it to the much more commonly-used unicast routing. When running a business with customers located in many different places, be it across the United States or around the world, knowing the difference can help you understand which architecture would be best for your reliability and performance needs. Unicast: One IP, One Server, One Location A Simple, Commonly-Used Architecture Because it is easier and inexpensive to implement, much of the Internet today is confi gured using unicast routing. The Internet is made of The easiest way to interconnected nodes – physical devices, often servers, that are able to understand how send, receive, and forward the information sent to it. IP addresses are anycast routing identifying numbers (and letters with IPv6) that tell the network where works is to compare to fi nd a node. With unicast, one IP address is mapped to one node that it to the much more physically resides in one location. commonly-used Setting up unicast is very straightforward, because the IP address only unicast routing. needs to resolve to the one environment where your content, data, and applications are stored. Ensuring just one server is up, running, and available is much easier than maintaining multiple locations. When you are connecting from one node (for example, your laptop) to another, such as a web server, routers will use their internal “map” to determine the shortest path to get from one device to the other. Routers send data sets, known as packets, to other routers that in turn send the same packet to other routers until the packet fi nally arrives at the server broadcasting the IP address. Each of these packet hand-offs are known as hops. Anycast vs Unicast: What a Global Business Needs to Know 2 With unicast, no matter where you are in the world, the last hop will always be to the same physical location. If your server is located in New York and is setup with unicast, a customer in New Jersey will have many fewer hops in their route to your server than a customer in Hong Kong will. Because of this, the New Jersey customer will always have a much faster and more reliable experience than the Hong Kong customer will. Downsides and Risks Although unicast is by far the easiest to set up, it is not always the fastest, most secure, or most reliable. If you’ve ever seen an error message that your IP address is already in use when trying to connect to a network, or that an IP wasn’t available when you were trying to connect to it, you’ve experienced some of the limitations of unicast. Performance can be highly variable with unicast, depending on where your users are located. If you have customers and business partners accessing your content from all across the country or the world, only the ones physically closest to your server’s location will experience the best performance. Unicast is also more prone to downtime and outages, because there is no redundancy in place if your server goes offl ine, even if just for routine Although unicast is maintenance. If your server fails or needs to be upgraded, your data and by far the easiest applications will be unavailable until the server is brought back online. to set up, it is not Most seriously, unicast is very vulnerable to DDoS (distributed denial of always the fastest, service) attacks. A DDoS attack generates an overwhelming amount of web most secure, or most traffi c and directs it at one server, overloading its resources and causing it reliable. to fail. The data and applications on your server will be unavailable until the attack is over – and often long after, as your system recovers. Anycast: One IP, Many Servers, Many Locations A Robust, Distributed Solution An alternative to unicast architecture is anycast routing, which is often a good fi t for businesses with customers across large geographic areas, such as the East Coast and West Coast of the United States, or across Europe and Asia. Anycast allows multiple servers to become accessible from a single IP address. This is done by using a specifi c confi guration of global Internet routing known as the Border Gateway Protocol or BGP. Once it is properly set up, you can have as many servers in as many locations as you need – all accessible from a single IP address, such as 172.16.254.1 (IPv4), or 2001:0db8:85a3:0000:0000:8a2e:0370:7334 (IPv6). Some well-known IP addresses include Google’s 8.8.8.8, and Cloudfl are’s 1.1.1.1, which both serve as public DNS services that help people browse the web faster and more quickly. Anycast vs Unicast: What a Global Business Needs to Know 3 Improved Performance If you have servers all around world that are anycasted, the number of hops your customer’s requests have to take to access your content and applications will go down dramatically. You could have a customer in China’s request sent to a Hong Kong datacenter, while a customer in New Jersey’s request could go to a datacenter in New York City. Anycast will signifi cantly improve your customer’s experience by ensuring they are always being served by the location physically closest to them. You can also use anycast to improve performance on internal network architectures, not just Internet-based platforms. Even better, anycast routing is possible on both IPv4 and IPv6 networks. 20ms 9ms United States United States United States 100ms 10ms United States England Ireland Ireland 200ms 15ms France Spain Spain With unicast routing, users geographically When anycast routing is used, customers further from your server will experience slower experience lower latency by connecting to the performance. server that is physically closest to them. Seamless Failover When you have multiple servers “sitting” behind one IP address with anycast, you can ensure your content and applications will always be available, 100% of the time. Let’s say your business has 10 locations around the United States, and each location is unicasted. Then, the New York location experiences a failure and goes offl ine. In this scenario, your service in that region would be offl ine and a user in New Jersey would have to wait until the physical server is restored and brought back online. Anycast vs Unicast: What a Global Business Needs to Know 4 Now let’s say your 10 locations around the United States utilize anycast and are accessible by one IP address. When the New York location fails, your customer in New Jersey will be quickly redirected to a server in Virginia, adding only a few milliseconds of access time, instead of leaving them frustrated and waiting, possibly hours or even days, for the New York server to be repaired. IP Unavailable 9ms United States United States United States IP Unavailable 10ms England Ireland France Ireland IP Unavailable 20ms France Spain Spain With a unicast infrastructure, if your server goes If your infrastructure is anycasted, in the event of down for any reason, users must wait until that a failure at one location, users will be seamlessly location comes back online. rerouted to the next closest location. Security Because your content is available from multiple servers in multiple locations, anycast will protect your network from DDoS attacks. In a DDoS attack originating from one location, malicious users will try to overload one of your servers. With anycast, even a successful attack of this type would only take one location offl ine, leaving your other locations available and ready. If a DDoS attack comes from multiple areas, their traffi c will be distributed among all of your locations equally, thereby reducing the chance that any one of your servers will go offl ine. For an additional level of protection, anycast can also be confi gured to work with services from leading DDoS mitigation service providers, including Prolexic and Arbor Networks. Anycast vs Unicast: What a Global Business Needs to Know 5 All users are served by a single physical location in Providing anycast routing with low-latency a unicast setup, making it simple and inexpensive performance and seamless failover requires a to deploy on your own. large investment in infrastructure and services. Downsides of Anycast While there are many benefi ts of anycast, one big downside of deploying your own anycast infrastructure is cost. The price of installing your servers in highly secure, well-connected, datacenters across the world can be daunting. You’ll end up juggling and paying for multiple datacenter operators, connectivity providers, and network technicians. If you have On top of all that, you have the cost of monitoring and troubleshooting customers across each location, and ensuring each one is online and available – and that’s the United States just to make sure the infrastructure is ready, without including the cost of a and even around the network expert to confi gure, monitor, and optimize your anycast routing. world, demanding high performance A Flexible, Reliable Anycast Provider and zero downtime, One way to both minimize those costs, and get all the benefi ts of anycast is an anycast routing by partnering with a provider like NetActuate for routing and infrastructure.